/* ISC license. */

#include <skalibs/uint64.h>
#include <skalibs/sha512.h>
#include "sha512-internal.h"

static uint64_t ror (uint64_t n, unsigned int k)
{
  return (n >> k) | (n << (64 - k)) ;
}

#undef Ch
#undef Maj
#undef S0
#undef S1
#undef R0
#undef R1

#define Ch(x, y, z)  ((z) ^ ((x) & ((y) ^ (z))))
#define Maj(x, y, z) (((x) & (y)) | ((z) & ((x) | (y))))
#define S0(x)      (ror((x), 28) ^ ror((x), 34) ^ ror((x), 39))
#define S1(x)      (ror((x), 14) ^ ror((x), 18) ^ ror((x), 41))
#define R0(x)      (ror((x), 1) ^ ror((x), 8) ^ ((x) >> 7))
#define R1(x)      (ror((x), 19) ^ ror((x), 61) ^ ((x) >> 6))

void sha512_transform (SHA512Schedule *ctx, unsigned char const *block)
{
  static uint64_t const K[80] =
  {
    0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL,
    0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL,
    0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
    0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL,
    0xd807aa98a3030242ULL, 0x12835b0145706fbeULL,
    0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
    0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL,
    0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL,
    0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
    0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL,
    0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL,
    0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
    0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL,
    0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL,
    0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
    0x06ca6351e003826fULL, 0x142929670a0e6e70ULL,
    0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL,
    0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
    0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL,
    0x81c2c92e47edaee6ULL, 0x92722c851482353bULL,
    0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
    0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL,
    0xd192e819d6ef5218ULL, 0xd69906245565a910ULL,
    0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
    0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL,
    0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL,
    0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
    0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL,
    0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL,
    0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
    0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL,
    0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL,
    0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
    0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL,
    0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL,
    0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
    0x28db77f523047d84ULL, 0x32caab7b40c72493ULL,
    0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL,
    0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
    0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL
  } ;
  uint64_t w[80] ;
  uint64_t h[8] ;
  uint64_t t[2] ;
  unsigned int i = 0 ;

  for (; i < 16 ; i++) uint64_unpack_big((char const *)block + (i << 3), w + i) ;
  for (; i < 80 ; i++) w[i] = R1(w[i-2]) + w[i-7] + R0(w[i-15]) + w[i-16] ;
  for (i = 0 ; i < 8 ; i++) h[i] = ctx->h[i] ;
  for (i = 0 ; i < 80 ; i++)
  {
    t[0] = h[7] + S1(h[4]) + Ch(h[4], h[5], h[6]) + K[i] + w[i] ;
    t[1] = S0(h[0]) + Maj(h[0], h[1], h[2]) ;
    h[7] = h[6] ;
    h[6] = h[5] ;
    h[5] = h[4] ;
    h[4] = h[3] + t[0] ;
    h[3] = h[2] ;
    h[2] = h[1] ;
    h[1] = h[0] ;
    h[0] = t[0] + t[1] ;
  }
  for (i = 0 ; i < 8 ; i++) ctx->h[i] += h[i] ;
}
